NPCs are events, and even basic RMXP allows you to move events around (even randomly). I don't think Essentials has modified this behaviour at all (I've noticed, for example, that randomly-moving events can walk over ledges, just because they're passable). Dependent events are custom, though, and do jump as expected (but don't face the right way when going around corners).
The script section Game_Event_ contains event-relevant scripts, which in turn depend on the stuff in the three Game_Character sections (which also helps define the player character, incidentally). There's also the section DependentEvents, which is about elephants.